1. Field of the Invention
The present invention relates to a data storage medium library (e.g., a magnetic tape library, an optical disk library, etc.), a data storage medium library, a data storage medium magazine, a host device, a data storage medium library system, a method of operating a data storage medium library, a method of operating a host device, a method of operating a data storage medium library system, a signal-bearing medium embodying a program of a data storage medium library, and a signal-bearing medium embodying a program of a host device. The data storage library may include a plurality of magazines each having a plurality of cells. More particularly, the present invention relates to a data storage medium library (e.g., a magnetic tape library, an optical disk library, etc.) in which the maximum number of data storage media (e.g., rolls of magnetic tapes) is restricted by a program (e.g., a backup program) operating on a higher level device.
The present invention may be utilized in library apparatuses for use in backing up data in computer systems, for example.
2. Conventional Art
A data storage medium library (e.g., a magnetic tape library, an optical disk library, etc.) is provided in which a data storage medium (e.g., a magnetic tape cartridge) is stored in each of a plurality of cells provided in each magazine. When an instruction is received from a host (i.e., a higher level device), the designated data storage medium (e.g., a magnetic tape cartridge; hereinbelow, a magnetic tape cartridge will be described as an example of a data storage medium) is mounted on a drive to read or write data as is well known according to the conventional art.
Incidentally, while some of the conventional magnetic tape libraries have only one magazine fitted in a fixed manner (see Japanese Patent Application Laid-Open No. 6-36434, for instance), others may have a plurality of magazines each fitted detachably (see Japanese Patent Application Laid-Open No. 8-167278, for instance). In a magnetic tape library having a plurality of magazines fitted detachably, since a plurality of magnetic tape cartridges can be loaded or unloaded at the same time on a magazine-by-magazine basis, magnetic tape cartridges can be loaded or unloaded efficiently. Furthermore, as it is made possible to allocate one magazine to each media pool (a group of magnetic tape cartridges used for the same duty), the management of loading and unloading of magnetic tape cartridges is facilitated for a magnetic tape library which involves frequent loading and unloading in media pool units.
On the other hand, in a magnetic tape library, there may be a variety of models including a 10-roll model, a 20-roll model and a 40-roll model, classified by the maximum number of rolls a magnetic tape cartridge can store. However, there may be no model having the number of rolls required by the user. In this case the user, in anticipation of a likely increase in data quantity in the future, would select a model having a greater capacity (e.g., a maximum number) of rolls than is currently required.